我在尝试创建symfony项目时遇到以下错误。在我尝试启动另一个项目之前，这一直运作良好。请帮助。
$ php composer.phar create-project symfony/framework-standard-edition BookSite
Installing symfony/framework-standard-edition (v2.6.3)
- Installing symfony/framework-standard-edition (v2.6.3)
Loading from cache
Created project in BookSite
Loading composer repositories with package information
Installing dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.
Problem 1
- sensio/distribution-bundle v3.0.12 requires sensiolabs/security-checker ~2.0 -> satisfiable by sensiolabs/security-checker[v2.0.0].
- sensio/distribution-bundle v3.0.13 requires sensiolabs/security-checker ~2.0 -> satisfiable by sensiolabs/security-checker[v2.0.0].
- sensio/distribution-bundle v3.0.14 requires sensiolabs/security-checker ~2.0 -> satisfiable by sensiolabs/security-checker[v2.0.0].
- sensio/distribution-bundle v3.0.15 requires sensiolabs/security-checker ~2.0 -> satisfiable by sensiolabs/security-checker[v2.0.0].
- sensiolabs/security-checker v2.0.0 requires ext-curl * -> the requested PHP extension curl is missing from your system.
- Installation request for sensio/distribution-bundle ~3.0.12 -> satisfiable by sensio/distribution-bundle[v3.0.12, v3.0.13, v3.0.14, v3.0.15].
答案 0 :(得分：0)
安装php扩展程序：